Lens blocking



V I May 19,1925. I 1* 1,538,651

A. FELLOW LENS BLOCKING Filed July 17, 1919 i I 4 IZ v FIBI INVENTOR ARTHUR FELLOW ATToRNEYs ARTHUR FELLOW, or soo'rnesrroen, it

PATENT OFFICE.

AS SACI-IUSE'ITS, ASSIGNOR TO AMERICAN OPTICAL COMPANY, OF SOUTHBBIDGE, MASSACHUSETTS, A. VOLUNTARY ASSO- CIATION OF MASSACHUSETTS.

LENS BLOCKING.

Application filed July 17,

To all whom it may concern:

Be it known that I, ARTHUR PnLLow, a citizen of the United States, residing at Southbridge, in the county of Vorcester and State of Massachusetts, have invented certain new and useful Improvements in Lens Blocking, of which the following is a speciflcation.

Previous to my invention it has been customary to block or mount lenses on a holder for the grinding operation by covering the member on which the lens is to be blocked with a coating of pitch or suitable adhesive and then to apply a warmed lens to the pitch or adhesive to cause the adhesive to properly grasp the lens and hold it in place.

This has been almost exclusively a hand .proposition, requiring hand labor for positioning the lenses and the results have been largely dependent on the individual skill of the operator in positioning the lenses.

It is, therefore, the purpose of my present invention to provide a novel and improved manner of blocking lenses particularly adapted for blocking of lenses for individual grinding, in which it will be possible to so position the lens with respect to the block that the face of the lens to be operated upon will occupy a predetermined relation to the body of the block and thus under ordinary conditions to the axis of the grinding tool, irrespective of the curvature or tilt of the face of the block with respect to its body portion.

A further object of the present invention is the provision of a novel and improved process of blocking lenses which will enable the operation to be practically automatically operated and do away with the necessity of specially skilled workers for handling the same.

Other objects and advantages of my improved construction should be readily'ap'parent by reference to the following specification taken in connection with the accompanying drawings, and it will be understood that I may make any modifications in the specific details of construction shown and described within the scope of the appended claim without departing from or exceeding the spirit of my invention.

Figure I represents a sectional view of one form of apparatus for carrying out the main step of my process.

1919. Serial No. 311,406.

Figure II represents a similar viewshowing the lens blocked.

In the drawings, the numeral 1 has been employed to denote the frame of an improved blocking machine or apparatus forming a part of a co-pending application, said frame having rising from the base the stud 2 bearing the lens support 3 and having further slidably engaged therein the plunger shaft 4 having a tapered lower end 5 receiving the lens block 6. The holder 3 is provided with an upstanding lens rest flange 7 and lateral lens engaging flange 8, the lens blank 9 resting on the flange 7 and being laterally positioned by engagement with the flange 8. In the carryboth the lens blanks 9 and the blocks 6 as by placing them within the heating oven, or any other suitable manner. Ithen remove from the source of heatalens blank 9 placing it in proper position upon the lens holder, which it will be noted engages the face of the lens to be ground so that the lens is, therefore, positioned according to such face. Similarly I place on the plunger portion 5 the heated block 6, the plunger being held in raised position. I then place upon the lens and between the lens and block, a slab or block 11 of the pitch or heat softenable retaining adhesive, after which the plunger is depressed, as by the handle 12, until the combined heat of the lens and block have so softened the pitch 11 that it flows out and slightly protrudes at the upper edge of the lens, as is clearly illustrated in Figure II. \Vhen the adhesive has reached this stage it will be understood that it has flowed over the entire upper surface of the lens and is deposited in a layer between the lens and the block 'and when allowed to cool will satisfactorily ad here to and hold together both of said parts. It will further be understood that in the event the surface of the block should be uneven or tilted with respect to the axis on which it is designed to rotate, that the adhesive will have substantially filled in this inequality and will be thinner on the high side and thicker on the low side so the lens surface to be ground will be in proper relation to the axis of the block and minimum grinding of the blank to produce the desired curve will be required, while the blank itself, if of uniform thickness at the outset will be ing out of my process I first suitably heat of uniform thickness when the grinding operation has been completed in spite oi the uneven face of the block on which it IS mounted.

shown the lens as resting upon the lower member with the adhesive block 11 therepressed down against the block by operation of a suitable positioning lIlODllJOY'ODlllB plunger, or in other words, a-suhstantial reversal of the several-parts illustratedi in Figures'l and II, without in any way departing from the features of the present process. 7

I clann The process otblo'cking lenses consisting n heating the lens and lens block, supportlng the lens on the lace \\'l1lCll is to he suhsequently ground, placing -a piece ot -heat It is to be understood that while I have sottenable adhesive 'on the opposite face of the lens, the said adhesive having 21 5111211101 diameter than either the block or the lens, and then bringing the heated block into engageinentwith thesaid adhesive whereh v to soften the adhesive and to cause extrusion thereof so as to unite thenparts inpredetermined relation.

In testimony whereof I have atlixed n signature, in presence ot'two witnesses.

ARTHUR PELLOTY.

\Vitnesses v Anon G'bIIASK ELL,

H. E. COLEMAN. 

